The DERBYSHIRE CAVER No 146 Autumn 2017 The Bottomless Pit lake, Speedwell Cavern IN THIS ISSUE – • John Gunn on water tracing at the Bottomless Pit • Bob Mehew’s note on Access Controlling Bodies and CO2 • Adam Russell replaces the Mouldridge Mine gate • Dave Prime on a SUSS Freshers’ Meet Published by the £2.00 DERBYSHIRE CAVING ASSOCIATION £2.00 THE DERBYSHIRE CAVER No 146 Autumn 2017 Editor: Material for inclusion can be sent hand-written or via email. Mike Higgins Please send contributions for the next issue as soon as they are ready. 56 Robin Hood Crescent Edenthorpe The views expressed in this publication are not necessarily those of the Doncaster editor nor of the Derbyshire Caving Association. DN3 2JJ Email: [email protected] The website of the Derbyshire Caving Association is at: www.theDCA.org.uk CONTENTS: Editorial . 3 CO2 in the Monyash Area . 3 The Bottomless Pit – Water Depth and Water Tracing . 4 Mouldridge Gate Replacement . 9 Access Controlling Bodies, CO2 and the HSW Act . 11 Freshers’ Meet (it was only short) . 13 Photographs from the Editor. 16 Cover photograph by the late Paul Deakin courtesy of John Harrison THE DCA - WHAT WE DO AND HOW TO JOIN US DOING IT The aim of Derbyshire Caving Association (DCA) is to protect the caves and promote good caving practice within the Peak District and surrounding areas. Membership is open to all clubs, individuals and outdoor activity providers with an interest in caves and caving or mine exploration. Check out the DCA website for further information (www.theDCA.org.uk). Membership enquiries should be made to the Secretary at [email protected]. The newsletter of the DCA has been in publication for over fifty years and provides a forum for cavers in the Peak District. The Editor welcomes contributions from all cavers, whether DCA members or not. News, articles, photographs, letters for publication, etc, should be posted or emailed to him at the above address, or give him a ring on 01302 882874. The Derbyshire Caver is posted free to DCA members; non-members may subscribe by sending a cheque for £9 (payable to DCA) for four issues, to the Secretary or Treasurer. Some back issues are also available for sale. Quarter-page adverts are £5 per insertion. Current issues of The Derbyshire Caver are available from the following outlets: The Old Smithy Teashop, Monyash; Peak District Mining Museum, Matlock Bath Editorial CO2 in the Monyash area This issue contains a wide range of articles, from DCRO had a callout to assist a cold, tired caver in another story about the good old days in SUSS by Knotlow Cavern on the evening of Saturday Dave Prime to an account by John Gunn of the 02/09/17, and it was reported that the levels of results of recent water tracing work at the CO2 in the system at the time may have Bottomless Pit Lake in Speedwell Cavern. We contributed to the casualty's condition. publish the note by Bob Mehew on CO2 and ACBs in the context of the Health and Safety at Work DCRO's underground party measured the level of legislation that led to his resignation as BCA Legal the gas to be 3·4% at the casualty site, and, while & Insurance Officer and there is the tale of the it isn't conclusive that the CO2 did contribute to Mouldridge Mine gate replacement by the hard- the issues leading to the casualty needing working Adam Russell. assistance, this level of gas is over twice the short- term exposure limit (STEL - the maximum level to Sadly, we have to report that Boyd Potts passed which a worker is allowed by law to be exposed, away on 17th September after being diagnosed and then only for a maximum period of 15 last May with inoperable lung cancer. Boyd was minutes). Chairman of Orpheus Caving Club and long represented them on DCA Council. Hopefully a full Cavers need to be aware that there may be a tribute will appear in the next issue. problem with CO2 levels in the Monyash venues (particularly in Knotlow Cavern, Hillocks Mine, As those of you who follow social media will be Whalfe Mine, Water Icicle Close Cavern, Raven aware, graffiti recently disfigured Holme Bank Mine and Lathkillhead Upper Series) and should Chert Mine at Bakewell. A joint clean-up team be advised to exercise due caution. from Masson Caving Group and Peak District Mines Historical Society was organised by Paul I have recently (July 2017) taken measurements at Chandler and the worst has now been dealt with. Water Icicle and Lathkilhead Upper Series and Thanks go to Paul, to Fatima and Vicky from found depletion of oxygen to be of the order 2·4% Masson and to Adam, Chris and Dave from to 3·3%, and it is reasonable to assume that PDMHS. depleted oxygen is replaced by a similar amount of carbon dioxide. As mentioned in the Editorial of the Spring issue of The Derbyshire Caver, Jenny Potts will be standing Following up on the Knotlow situation, Pete Dell down as DCA Secretary at the next AGM on 24th and I descended Knotlow with a multi-gas monitor February 2018. She has done this job and others at which recorded oxygen levels and a single gas DCA since time immemorial and will be a hard act carbon dioxide meter, with the intention of taking to follow. Nevertheless, the post has to be filled some atmospheric readings along the climbing and if you would like to help the Peak District’s shaft route, as far as Waterfall Chamber. regional caving body in its essential work then please contact DCA. The conditions underground were markedly different to those found by the team on 02/09/17, Finally, a plug for a recent publication. TSG 19, the with oxygen staying above our current alarm 2017 Journal of the Technical Speleological Group, setting of 19% (although this should be 19·5% in a is now available. It contains over 200 pages and working environment) and carbon dioxide went around 250 mainly colour photographs plus 18 over the statutory low alarm point of 0·5% in Pearl surveys. Put together by Phil Wolstenholme it Chamber (reading was 0·6%) and rose to just represents excellent value at £25 – order it via the around the STEL point of 1·5% at the top of the TSG website. Waterfall Pitch. However, without the meter, it would have been difficult to tell that the air was any different to that on the surface. Mike Higgins Alan Brentnall 3 The Bottomless Pit Lake, Speedwell Cavern, Castleton: Water depth and water tracing Preamble: The elevations in the following article were recorded (Figure 2). For 94% of the time the were supplied to the author by Wayne Sheldon in surface of the lake was at or below 212.5m aOD August 2017 from the Castleton Survex model. In and there were 11 storm events when the late September Wayne issued updated Survex elevation was >215m. Of those 11 storm events elevations that were 3.9m above those previously five achieved depths above 226.8m resulting in supplied placing the Bottomless Pit platform at inundation of the viewing platform and the 230.1m aOD instead of 226.8m. As the latter is highest elevation reached was 228.5m aOD. virtually the same as the elevation used in the 1990s the author is of the opinion that there has Rieuwerts & Ford (1985, page 148) state that been a mistake but as of 14 October no-one had "Flood waters soon back up so the outlet is very been able to provide an explanation. Hence, the restricted". The recorded data show that the first article uses the elevations as originally supplied. If part of this statement is true as the depth these are subsequently found to be in error a increases rapidly, commonly at a rate of 1m in 5 corrigendum will be included in the next issue of minutes and with a maximum of 1.32m in 5 the Newsletter. minutes. However, as the volume of water flowing into the Pit from the Far Canal decreases the lake The Bottomless Pit is a large vein cavity at the end also drains rapidly with falls of up to 0.84m in 5 of the Near Canal in Speedwell Cavern. Tourists minutes. The water surface area varies with height visiting Speedwell are transported by boat along but if one uses the figures that Marsden (1991) the canal to the Bottomless Pit where they alight quotes as the area at normal water level (12m * onto a platform that was constructed by lead 9m) then a fall of 0.84m in 5 minutes equates to a miners in the 18th century. From the platform, flow of 302 L/s out of the lake. Moreover, if water they look down onto a lake that is 12m long, 9m was continuing to enter the Pit whilst levels were wide and has a maximum explored depth of 8m at falling then the actual flow out must have been in its normal water level although the vein cavity excess of 302 L/s. Clearly then the main outlet (or must have been deeper before the miners used it outlets) from the Pit is not restricted but it must as a convenient dump for waste rock (Marsden, be at, or perhaps above the 211.8m aOD level at 1991). Based on data in a Survex model of the which water rests for most of the year. An obvious Peak-Speedwell cave system Sheldon (pers.